The Autobag Patents disclose a packaging technique in which a chain of interconnected open plastic bags are used. In the earliest commercial form a roll of these bags was mounted on a mandrel and the mandrel was positioned in a box. A blower was connected to the box. Bags were dispensed by feeding them closed end first, out of a slot in the box. Air from the blower exiting through the same slot would inflate each bag as it came out of the box. A product was manually inserted into the inflated bag and the bag was separated from the chain. The loaded and separated bag was then usually closed and heat sealed.
The boxes used in the described earliest commercial form were disposable shipping containers that also served as dispensing containers. As a next step in the evolution of equipment for effecting packaging with a chain of open bags on a roll, manually controlled dispensing machines were developeld. Each .machine was adapted to receive a coil of interconnected open bags. The bags were fed through a dispensing opening in the machine and then vertically downwardly along a path of travel. In a typical operation, after a bag had been blown open an operator would manually insert a product. The operator would then manually separate the loaded bag from the chain of bags and insert its open end into a heat sealer. Concurrently with the separation of the loaded bag the operator would feed the chain of bags to bring the next succeeding bag into the loading station.
More sophisticated automatic equipment has been developed for loading and sealing chains of open bags on a roll. An example of such equipment is that disclosed and claimed in the H-100 Patents. With that equipment, bags are automatically fed to a loading station. In addition, they are automatically sealed and separated from the chain after products have been loaded. The H-100 machines, like earlier machines until the invention of the Wig Wag Patent was made, used bags on a roll.
Manufacture of rolls of open bags has presented a problem. When the bags are used it is necessary to feed the bags closed end first. This has meant that as the bags have been wound into a coil they have been fed onto the coil being formed open end first. The bags must be fed quite slowly during a winding operation to avoid blowing the bags open excessively and tearing the web.
In order to achieve reasonable and efficient production speeds, bags have been fed closed end first during manufacture and coiled. Thereafter a "rewind" operation is performed at slow speeds to provide a finished coil from which bags are fed closed end first.
The Wig Wag Patent discloses a system by which bags were fed closed end first into a dispensing box and then dispensed on a first in-first out basis. To accomplish this, bags were arranged in a plicated array of horizontal layers. While this system has enjoyed some success, especially with relatively large bags, rewinding has continued to be used for most applications of Autobag products. While rewinding is expensive, in terms of overall efficiency it has prooved to be more efficient than the approach of the "Wig Wag Patent for many applications because forming a plicated array in accordance with the teaching of that patent-slows the overall bag formation operation.
Disclosure of the Invention
Practice of the present invention overcomes the drawbacks of the prior art by forming a coil of interconnected open bags in a novel and improved manner which permits bags to be fed from the center of a coil. The bags of the coil of this invention are preferably those that have been sold commercially under the trademark AUTOBAG and described in the Autobag Patents. Since the bags are fed from the center of the coil they are fed on a first wound, first unwound basis. This permits the bags to be wound closed end first and unwound closed end first without the expense of the time consuming prior rewind practice.
Dispensing bags by pulling them from the center or hole in an annular coil of bags presents a problem. With prior coils it could not effectively and reliably , be done even if it has occurred to someone to try to, because with such coils bags tend to "bunch up" and resist coming from the center to the point where the bags tend to separate from the web along the preformed lines of weakness.
The solution to the "bunching" problem lies in the discovery that if the diameter of the central aperture or hole in the coil is at least as great as the width of a web in the form of a chain of flattened interconnected bags, the bags may be fed easily and directly from the center hole. Accordingly, webs of open but interconnected and flattened bags are formed by known processes and then fed closed end first and wound into coils of bags each having a central opening of a diameter at least as great as the width of the web.
To accomplish the feed from the center hole and control the feed of a web from a dispensing location to a product loading station, a novel web feed dispenser has been devised. This mechanism includes a bag supporting rotatable table mounted on a base. The table includes a coil supporting surface which is horizontal when in use. A tapered mandrel is connected to and projects upwardly from the table. A shaft for the tapered mandrel and table projects upwardly from a base and the table and tapered mandrel are journaled on this shaft.
The dispensing mechanism also includes a feed control mandrel. The feed control mandrel is preferably pivotally and removably mounted above the tapered mandrel. The feed control mandrel includes a rotatable cylindrical roll which is rotatable about the axis of the feed control mandrel.
In the preferred embodiment a support bracket is mounted on the tapered mandrel shaft. The support bracket has an upwardly directed open ended slot. A hanging bracket carries the feed control mandrel. The hanging bracket includes a pin which is removably received in the slot to provide a pivotal support for the feed control mandrel. The feed control mandrel includes a drive section which engages a driven section on the tapered mandrel. An adjustment mechanism is interposed between the brackets to adjust the angular relationship between the mandrels and the engagement of the drive and driven sections.
In dispensing, a coil of bags is mounted on the support surface and around the tapered mandrel. The feed control mandrel is then pivotally connected to the tapered mandrel. Bags are fed closed end first from the center of the coil along a path. The path angles upwardly from the center of the coil, reeves over a portion of the tapered mandrel, thence continuing upwardly over a portion of the feed control mandre.
The web path includes a span from the feed control mandrel to a horizontally journaled idler roll. In this span the web under goes a slight twisting action to bring its major dimension horizontal. After passing over this horizontal idler roll, the web path continues to a loading station where bags are sequentially inflated and loaded. Once loaded, they are typically heat sealed and separated from the web in the manner disclosed in the H-100 Patents.
Another of the advantages of the present invention is that a series of coils of bags may be spliced together and stacked to provide trouble-free automatic dispensing over a long time frame without operator intervention. To accomplish this, the inner end of the bottom coil of a stack is connected to the outer end of the next to bottom coil and so on so that as the upper most coil is paid out it is spliced to the inner end of the next coil and the stack will automatically commence bag feeding from the next coil.
Accordingly, an object of the invention is to provide a novel and improved system for dispensing bags in the form of a web of interconnected open bags, a novel and improved coil of bags and a novel and improved dispensing mechanism.
Other objects and a fuller understanding of the invention may be had by referring to the following description and claims taken in conjunction with the accompanying drawings in which: